Prior art connectors which are currently in wide use for splicing and for connecting insulated conductors in telephone and other electrical circuits generally include a plurality of contact elements which are mounted in terminal blocks. The contact element must be such that it provides a reliable connection which is easily made and such that it is relatively small to minimize space requirements.
Electrical connections for telecommunications have been made in a number of ways. One of these is by way of terminals which include a post and nut arrangement. In those, an end of an insulated conductor is bared and wrapped about a threaded post with a nut being turned along the post to engage the conductor end and to hold it in engagement with a terminal block from which the post extends. Typically, an opposite end of the post is formed to have another conductor wrapped thereabout. While this arrangement results in a reliable connection, it is labor intensive and escalates costs.
Another connection arrangement includes an element which when inserted into a dielectric housing is caused to pierce an insulated conductor and establish electrical engagement therewith. An example of this kind of arrangement is the familiar modular plug in which blade-like terminals are seated in a housing such that tangs of the terminals pierce tinsel conductors and make electrical contact therewith. See for example U.S. Pat. No. 3,860,316 which issued to E. C. Hardesty on Jan. 16, 1975. One problem with these kinds of connectors lies in their relative inability to pierce solid conductors as opposed to stranded or tinsel conductors. Desirably, a connector for use in a multiconductor system is adaptable to interconnect solid as well as stranded conductors.
A connector which is widely used in telecommunications for interconnecting insulated conductors in which the conductive elements are solid is one which is called a split beam connector. A plurality of metallic contact elements are mounted in a dielectric housing. Each of the contact elements, in one well-known product, includes a center portion with beams extending colinearly therefrom. Each of the beams is bifurcated with the furcations of each forming a conductor-receiving slot. To establish a connection, an insulated conductor is moved into one slot and another conductor into the opposite slot. Surfaces that define the entrances to the slots and the slots themselves are configured to nick the conductive element of each conductor to establish an electrical connection between the conductors. See for example U.S. Pat. No. 3,496,522 which issued on Feb. 17, 1970 in the names of B. C. Ellis et al and U.S. Pat. Nos. 3,611,264 and 3,772,635.
While the split beam connector just described overcomes problems associated with the terminal post and piercing type connectors, it presents other problems. For example, special features must be included to insure continuing connections between the furcations and the conductors notwithstanding changes to the outer diameter of the insulated conductor which are caused by temperature cycling. Another problem with the split beam connector relates to its capability of using one slot to terminate two or more conductors or conductors of different gauges. When the insulated conductor first placed in the slot is moved farther inwardly, it tends to spread apart the side walls of the furcations which define the slot and which in prior art connectors are generally resilient. Disadvantageously, the surfaces which define the slot can be deflected to an extent that precludes the establishment of a satisfactory gas-tight connection with the conductive element of a second conductor that is moved into the slot.
Also, the conventional split beam connector does not provide an altogether effective connective mechanism for stranded conductors. When a stranded conductor is moved into the slot, the furcations which are resilient are deflected. The configuration of the conductor is deformed and the individual strand elements become rearranged in the slot with some diminution of the nicking of the elements.
While the prior art abounds with connectors for insulated conductors, it does not include one which overcomes the problems which have been discussed hereinbefore. For example, in U.S. Pat. No. 4,033,661, walls of an insulating body define an aperture extending transversely of and intersecting each of two stacked conductor-receiving channels. A cylindrical contact element includes one slot designed to make electrical contact with a conductor in one of the two channels and a second slot to electrically engage a conductor which is disposed in the other channel. Barrel type terminals which are shown in U.S. Pat. Nos. 3,860,318, 3,877,773 and 3,845,455 are rolled from sheet material and have walls which are sprung apart by inserted conductors. Should more than one conductor be moved into a slot, the spring characteristic of the walls favors the largest one. To overcome this, slots are formed transverse of the longitudinal slot to facilitate the movement of a conductor from one longitudinal slot to the other. However, in this arrangement, each portion of each slot can only establish a connection with one conductor. W. S. Pawl in his U.S. Pat. No. 3,377,611 discloses a solderless, rigid electrical connector of a thickness which is substantially greater than the diameter of a wire to be received in a parallel sided slot. As a result, the conductive element of a conductor is compressed as it is forced into the slot to maintain suitable contact.
What is needed for use in a multi-conductor connection system and what the prior art does not provide is a contact element which is capable of establishing and maintaining a suitable electrical connection with stranded, tinsel or solid wire-like conductors. Further, it should be able to establish and maintain electrical engagement with one or more conductors of the same or different gauge size in the same slot. With today's seemingly endless growth of telecommunications, there is still a need for an electrical connector that is relatively small and that fills the above needs.